Serious question, is the Geth Juggernaut really
good for Gold soloing?

I would recommend him against Cerberus. Phantoms cease to be troublesome, and Atlases are too slow to constantly pursue a Juggernaut, unlike Banshees. Dragoons would probably end up being the biggest issue, but even they're easily dealt with if you have a good weapon.---GT - Sheepman2342One does not simply skip Homing Grenades.